我怎么能得到一个NSDate对象的年/月/日，没有其他信息?我意识到我可以用类似这样的东西来做这件事:
NSCalendar *cal = [[NSCalendar alloc] init];
NSDateComponents *components = [cal components:0 fromDate:date];
int year = [components year];
int month = [components month];
int day = [components day];
但是对于像获取NSDate的年/月/日这样简单的事情来说，这似乎是一大堆麻烦。还有其他解决办法吗?
当前回答
iOS 8新增功能
ObjC
NSDate *date = [NSDate date];
NSInteger era, year, month, day;
[[NSCalendar currentCalendar] getEra:&era year:&year month:&month day:&day fromDate:date];
斯威夫特
let date = NSDate.init()
var era = 0, year = 0, month = 0, day = 0
NSCalendar.currentCalendar().getEra(&era, year:&year, month:&month, day:&day, fromDate: date)
其他回答
在Swift 2.0中:
let date = NSDate()
let calendar = NSCalendar(identifier: NSCalendarIdentifierGregorian)!
let components = calendar.components([.Month, .Day], fromDate: date)
let (month, day) = (components.month, components.day)
试试下面的方法:
NSString *birthday = @"06/15/1977";
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"MM/dd/yyyy"];
NSDate *date = [formatter dateFromString:birthday];
if(date!=nil) {
NSInteger age = [date timeIntervalSinceNow]/31556926;
NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:date];
NSInteger day = [components day];
NSInteger month = [components month];
NSInteger year = [components year];
NSLog(@"Day:%d Month:%d Year:%d Age:%d",day,month,year,age);
}
[formatter release];
我这样做....
NSDate * mydate = [NSDate date];
NSCalendar * mycalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSCalendarUnit units = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay;
NSDateComponents * myComponents = [mycalendar components:units fromDate:mydate];
NSLog(@"%d-%d-%d",myComponents.day,myComponents.month,myComponents.year);
NSDate *currDate = [NSDate date];
NSCalendar* calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents* components = [calendar components:NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:currDate];
NSInteger day = [components day];
NSInteger month = [components month];
NSInteger year = [components year];
NSLog(@"%d/%d/%d", day, month, year);
如果你想从NSDate中获得单个的NSDateComponents，你肯定需要Itai Ferber建议的解决方案。但如果你想直接从NSDate到NSString，你可以使用NSDateFormatter。
